A high-rise building in Tehran engulfed by fire has collapsed, killing at least 30 firefighters and injuring 75 people.

Firefighters, soldiers and other emergency responders dug through the rubble, looking for survivors on Thursday.

Firefighters battled the blaze for several hours before the collapse.

Local news services caught the collapse live on camera:

https://www.youtube.com/watch?v=KvvCt5cAZdU

The fire appeared to be the most intense in the building’s upper floors, home to garment workshops where tailors cook for themselves and use old kerosene heaters for warmth in winter.

Police tried to keep out shopkeepers and others wanting to rush back in to collect their valuables.

Tehran’s mayor, Mohammad Bagher Ghalibaf, said there were “no ordinary civilians” trapped under the rubble, however, witnesses said some people had slipped through the police cordon and gone back into the building.

Tragic news today: many firefighters and civilians, they were rescuing, feared dead after collapse of #Plasco building in Tehran, Iran. pic.twitter.com/iTFL52ooX9

— Gerry Gray (@ggfire343) January 19, 2017

President Hassan Rouhani ordered Interior Minister Abdolreza Rahmani Fazli to investigate and report the cause of the incident as soon as possible.

He also ordered the ministry to ensure the injured were cared for and to take immediate action to compensate those affected by the disaster.

Emotional firefighters outside the collapsed Plasco building in Iran’s capital. Photo: AP/Vahid Salemi

The building came down in a matter of seconds, shown live on state television, which had begun an interview with a journalist at the scene.

A side of the building came down first, tumbling perilously close to a firefighter perched on a ladder and spraying water on the blaze and a thick plume of brown smoke rose over the site after the collapse.

Among those watching the disaster unfold was Masoumeh Kazemi, who said she rushed to the building as her two sons and a brother had jobs in the garment workshops occupying the upper floors of the high-rise.

“I do not know where they are now,” Kazemi said, crying.

In a nearby intersection, Abbas Nikkhoo stood with tears in his eyes.

Iranian firefighters try to exit the Plasco building before its collapse. Photo: EPA/Abedin Taherkenareh

“My nephew was working in a workshop there,” he said.

“He has been living with me since moving to Tehran last year from the north of the country in hopes of finding a job.”

Jalal Maleki, a fire department spokesman, earlier told Iranian state television that 10 firehouses responded to the blaze.

The Plasco building was an iconic presence on the Tehran skyline.

The 17-story tower was built in the early 1960s by Iranian Jewish businessman Habib Elghanian and named after his plastics manufacturing company.

It was the tallest building in the city at the time of its construction.